The invention relates to an arrangement in connection with a circulation lubrication system, comprising an intermediate tank, inlet channel means for feeding a lubricant into the intermediate tank, and outlet channel means for removing the lubricant from the intermediate tank, discharge means for emptying the intermediate tank, and measuring means arranged to start the discharge means when the level of the lubricant in the intermediate tank rises to a predetermined upper limit and to stop the discharge means when the level of the lubricant in the intermediate tank falls to a predetermined lower limit.
The above arrangements are presently well-known in connection with circulation lubrication systems. The conventional intermediate tank solutions are frequently implemented in such a way that two electric motor driven pumps, for example, are arranged in connection with the tank. The use of the pumps is controlled with starting and stopping liquid level switches. The pump starts when the level of the lubricant in the tank reaches the upper limit functioning as the starting level and stops when the level of the lubricant falls to the lower limit functioning as the stopping level. There are usually two pumps, whereby one of the pumps is in normal operation and the other is an emergency pump in case the pump in normal operation is affected by a failure and cannot empty the intermediate tank. The size of the intermediate tank is typically 100 to 600 liters.
Drawbacks of the conventional intermediate tank solutions include the complexity, and also the size of the tank, which is relatively large. Due to the complexity, the manufacturing costs have been high, and the large size of the apparatus has made its positioning more difficult in industrial premises, which are in many cases rather limited in area.
An object of the invention is to provide an arrangement by means of which the drawbacks of the prior art can be eliminated. This has been achieved by means of the invention. The arrangement according to the invention is characterized in that the discharge means comprise a pneumatic valve arranged to open, controlled by the measuring means, when the level of the lubricant is at the upper limit, and to let pressurized air flow into the intermediate tank, whereby the pressurized air is arranged to push the lubricant out of the intermediate tank through the outlet channel means, and to shut and prevent the flow of pressurized air into the intermediate tank when the level of the lubricant falls to the lower limit, and that a counter valve is arranged in the inlet channel means for the lubricant before the intermediate tank, seen from the direction of flow, the counter valve being arranged to prevent the flow of the lubricant out of the intermediate tank into the inlet channel means.
An advantage of the invention compared with prior art solutions is, above all, that a construction smaller and simpler than previously can be achieved. Thus, the manufacturing costs can be decreased by means of the invention, compared with the prior art, and the positioning of the apparatus in different industrial premises becomes considerably easier, compared with the use of conventional technology.